Cu and Ni minerals that have great economic value mostly exist in the form of sulfides, making them difficult to extract using hydrometallurgical processes. Currently, heap leaching is the most economical way to extract these metals from low grade ores. Copper recoveries of many chalcocite heap leaches report around 70% copper recovery. However, the chalcocite leaching reaction has several stages. The first stage leach is characterized by 50% copper extraction and the conversion of chalcocite into a second stage of covellite (CuS) which is very difficult to leach at ambient temperature.
Bio-heap-leaching is a hydrometallurgical process used to process low grade chalcopyrite ore as the cost of alternative routes of processing and refining are not economically viable. The limitation however of the heap leaching process is the long time it takes to leach the metal and the low total recovery that can be achieved. As heap leaching being a large scale atmospheric leaching process, neither temperature nor pressure can be changed.
Copper, a conductive metal, forms the basis of much of our manufacturing and electrical infrastructure. Yet, despite high demands for the metal, supply is not keeping pace. One of the chief reasons is that copper extraction faces steep technical challenges that have steadily pushed up capital expenditures. We propose to use a recent innovation called synthetic biology to greatly improve the efficiency and cost of copper extraction. Our method employs microorganisms that leach copper via a process called bioleaching. Despite the methods promise, however, some challenges remain.